Glasson, E. J., Buckley, N., Chen, W., Leonard, H., Epstein, A., Skoss, R., … & Downs, J. (2020). Systematic review and meta-analysis: mental health in children with neurogenetic disorders associated with intellectual disability. Journal of the American Academy of Child & Adolescent Psychiatry.

Psychiatric disorders are more common in children with intellectual disability and neurodevelopmental disorders.  This review describes five syndromes in particular that confer greater risk (Down Syndrome, 22q11.2 deletion syndrome, Fragile X syndrome, Williams syndrome, and Prader Willi syndrome) and their associated psychiatric co-morbidities.  

https://www.jaacap.org/article/S0890-8567(20)30008-3/fulltext?dgcid=raven_jbs_etoc_email